Thiolated paclitaxels for reaction with gold nanoparticles as drug delivery agents

A compound of formula 1

• wherein
• R1 is phenyl, tert-butoxy, or C1-6 alkyloxy;
• R2 is phenyl, 4-fluorophenyl, 4-methylphenyl, 2-furanyl, 2-thienyl, isopropyl, isobutenyl, cyclopropyl, 3-furanyl, 3-thienyl, or 2-propenyl;
• R3 is benzoyl, m-methoxybenzoyl, m -azidobenzoyl, or m -chlorobenzoyl;
• R4 is C(O)Rx where Rx is:
• H;
• C1-6 alkyl, optionally substituted with one to six halogen atoms, which may be the same or different;
• C3-6 cycloalkyl;
• or C2-6 alkenyl or hydroxyl;
• R5 is H;
• or methyl;
• or C(O)Rx, where Rx is:
• H, C1-6 alkyl, optionally substituted with one to six halogen atoms, which may be the same or different;
• C3-6 cycloalkyl;
• C2-6 alkenyl or hydroxyl;
• and
• M1 is sulfur bearing substituent linked to a colloidal metal particle, wherein the compound has a structure selected from the group consisting of structures 2-4, 6-11, 16-18, 27 and 33
• where n is an integer between 0 and 100, and X is said colloidal metal nanoparticle.